* { box-sizing: border-box; }
body { margin:0; font-family:'Microsoft YaHei','Segoe UI',sans-serif; background:#f3f6fa; color:#1f2d3d; font-size:14px; }

/* 登录 */
.mask { position:fixed; inset:0; background:linear-gradient(135deg,#0b2a4a,#14507f); display:flex; align-items:center; justify-content:center; z-index:10; }
.login-card { background:#fff; border-radius:12px; padding:32px 30px; width:340px; box-shadow:0 12px 40px rgba(0,0,0,.25); text-align:center; }
.login-card h2 { margin:0; color:#0b2a4a; font-size:20px; }
.login-card .sub { color:#667085; font-size:13px; margin:6px 0 20px; }
.login-card input { width:100%; padding:11px 12px; border:1px solid #cfd8e3; border-radius:8px; font-size:14px; margin-bottom:12px; }
.login-card input:focus { outline:none; border-color:#14507f; }
.login-card button { width:100%; padding:11px; background:#0b5cad; color:#fff; border:0; border-radius:8px; font-size:15px; cursor:pointer; }
.login-card button:hover { background:#0a4f95; }
.err { color:#c0392b; font-size:13px; min-height:18px; margin-top:6px; }

/* 头部 */
header { display:flex; align-items:center; gap:8px; background:#0b2a4a; color:#eaf2fb; padding:0 18px; height:56px; flex-wrap:wrap; }
.brand { font-weight:bold; font-size:16px; margin-right:14px; }
nav { display:flex; gap:4px; }
.tab { background:transparent; border:0; color:#c5d6ea; padding:8px 14px; border-radius:8px; cursor:pointer; font-size:14px; }
.tab:hover { background:rgba(255,255,255,.08); }
.tab.active { background:#14507f; color:#fff; }
.spacer { flex:1; }
.ghost { background:transparent; border:1px solid #3d6d9c; color:#c5d6ea; padding:7px 12px; border-radius:8px; cursor:pointer; }
.ghost:hover { background:rgba(255,255,255,.1); }

/* 统计卡 */
.stats { display:flex; gap:12px; padding:16px 18px 0; flex-wrap:wrap; }
.stat-box { flex:1 1 150px; background:#fff; border:1px solid #e0e7f0; border-radius:10px; padding:12px 16px; }
.stat-box .v { font-size:24px; font-weight:bold; }
.stat-box .l { color:#667085; font-size:13px; }
.stat-box.online .v { color:#1c7a47; }
.stat-box.offline .v { color:#b3402f; }
.stat-box.sess .v { color:#0b5cad; }
.stat-box.code .v { color:#9a5b0b; }

main { padding:16px 18px 30px; }
.tab-panel { display:none; }
.tab-panel.active { display:block; }
.card { background:#fff; border:1px solid #e0e7f0; border-radius:10px; overflow:hidden; margin-bottom:16px; }

table { width:100%; border-collapse:collapse; }
th,td { padding:10px 12px; text-align:left; border-bottom:1px solid #eef1f5; vertical-align:middle; }
th { background:#f7f9fc; color:#556070; font-weight:600; font-size:13px; }
tr:last-child td { border-bottom:0; }

.dot { display:inline-block; width:9px; height:9px; border-radius:50%; margin-right:6px; }
.dot.on { background:#1c7a47; } .dot.off { background:#b9c2cf; }
.code-val { font-family:Consolas,monospace; font-weight:bold; letter-spacing:.5px; }
.tag { display:inline-block; padding:2px 8px; border-radius:6px; font-size:12px; background:#eef2f7; color:#46566b; }
.tag.ok { background:#e3f0e8; color:#1c7a47; }
.tag.bad { background:#fdeeee; color:#b3402f; }
.act { color:#0b5cad; cursor:pointer; margin-right:10px; font-size:13px; }
.act.danger { color:#b3402f; }
.act:hover { text-decoration:underline; }
.muted { color:#8a94a6; }

/* 表单 */
.form-card h3 { margin:0 0 10px; font-size:15px; color:#0b2a4a; }
.form-row { display:flex; gap:12px; flex-wrap:wrap; align-items:flex-end; }
.form-row label { display:flex; flex-direction:column; font-size:12px; color:#556070; gap:5px; }
.form-row label.chk { flex-direction:row; align-items:center; gap:6px; padding-bottom:10px; }
.form-row label.grow { flex:1 1 200px; }
.form-row input,.form-row select { padding:8px 10px; border:1px solid #cfd8e3; border-radius:8px; font-size:13px; min-width:110px; }
.form-row button { padding:9px 18px; background:#0b5cad; color:#fff; border:0; border-radius:8px; cursor:pointer; font-size:14px; }
.form-row button:hover { background:#0a4f95; }

@media (max-width:720px){
  header { height:auto; padding:8px 12px; }
  .brand { width:100%; margin:2px 0 6px; }
  th,td { padding:8px; font-size:12px; }
}